HeidelToul: A Baseline Approach for Cross-document Event Ordering

In this paper, we give an overview of our participation in the timeline generation task of SemEval-2015 (task 4, TimeLine: CrossDocument Event Ordering). The main goals of this new track are, given a collection of news articles and a so-called target entity, to determine events that are relevant for the entity, to resolve event coreferences, and to order the events chronologically. We addressed the sub-tasks, in which event mentions were provided, i.e., no additional event extraction was required. For this, we developed an ad-hoc approach based on a temporal tagger and a coreference resolution tool for entities. After determining relevant sentences, relevant events are extracted and anchored on a timeline. The evaluation conducted on three collections of news articles shows that our approach – despite its simplicity – achieves reasonable results and opens several promising issues for future work.